The invention relates to a new multiwell filtration plate for high throughput applications in the nucleic acid technology, preferably in the 96-well or 384-well format.
In recent years, there has been an increasing trend towards automating the isolation and purification of nucleic acids. The reason for that is that biological methods are increasingly gaining acceptance in all research fields of modern biotechnology. Automation of the isolation and purification of plasma DNA has become an urgent prerequisite due to the DNA sequencing within the worldwide genome projects (for example, the human genome project). The need to develop automation variants is not limited only to the field of plasmid DNA isolation. The automated isolation of genomic DNA from different starting materials and amounts, as well as the isolation of RNA are increasingly gaining in importance. This involves all areas of basic molecular research and increasingly also the diagnostics area.
Methods of automated isolation of nucleic acids are realized at the present time by the use of microtest plates with built-in filter materials. Formats in use at the present time are so-called 96-well or 384-well microtest plates. However, presently available 96-well microtest plates with filter material are extremely expensive for high-throughput applications. This results from the relatively complicated manufacturing methods for bringing the filter material into the microtest plates such as described in U.S. Pat. No. 4,948,442. Moreover, none of the previously known microtest plates with filter insert realize sufficient protection against cross contamination of samples when used for the isolation and purification of nucleic acids. The reason for this is the much too short outlet 30 connecting piece at the bottom of the multiwell filtration plate.
A further problem is posed by the small capacity of the reaction cavities, such as those described in European patent No. 0,098,534.
It is an object of the invention to provide a multiwell filtration plate for nucleic acid technology, which is particularly suitable also for high throughput applications, provides protection against cross contamination of the samples and can be produced relatively inexpensively.
Another object is a method for producing the multiwell filtration plates of the present invention. The new multiwell filtration plate of the present invention has two individual parts, which are tightly connected with one another. A first part is a sample holder and the second part acts as an outlet part after filtration is completed.